Mankiw, Redistribution, Height Taxes, and Utilitiarianism

Via a distraught Conor Clarke, I see that not only did Greg Mankiw once write a cheeky paper arguing that maybe we should impose a height tax, he also goes in for some odd philosophical claims. To try to reconstruct his argument, he believes:

The main arguments in favor of redistributive taxation are grounded in utilitarianism.

Utilitarian theory supports taxing tall people more heavily than short people (this is the thesis of the paper).

Therefore, people should either sign on for the height tax or else abandon their support for redistribution.

He concludes with this:

A moral and political philosophy is not like a smorgasbord, where you get to pick and choose the offerings you like and leave the others behind without explanation. It is more like your mother telling you to clean everything on your plate. If you are a Utilitarian redistributionist, the height tax is like that awful tasting vegetable your mother served up because it is good for you. No matter how hard you might wish it wasn’t there sitting on your plate, it just won’t go away.

I think there are a ton of mistakes being made here. This goes back to a point I was making a while ago about how dangerous it is that the public discourse is so dominated by low-quality freelance philosophy done by people with PhDs in economics. I’m fairly certain that if Mankiw were to walk over to Emerson Hall he could find some folks (possibly T.M. Scanlon who I know sometimes reads this blog) who could explain to him that there’s little grounds for the belief that a commitment to utilitarianism is the main justification for redistributive taxation.

So point one is factually wrong.

But that aside, I think the “smorgasboard” argument is a confused way of thinking about moral reasoning. A great many crucially important questions in normative ethics are easy. Is it okay to murder Greg Mankiw to steal the money in his pocket? No, it isn’t. But a lot of foundational questions in ethical theory are hard. And a lot of meta-ethical questions are hard. Normal people don’t even understand what all of these questions are. And those of us who’ve thought a little bit about them, but decided not to go into the professional philosophy game may be aware that there are issues in these areas about which we’re uncertain. There’s a certain hyper-literal sense in which these questions all form a hierarchy. First I must decide where I stand on meta-ethics. Am I a reductive moral realist? A quasi-realist? A practical reasons theorist? An old-school “moral facts are facts too, damnit” moral realist? Are there theological issues in play? Then I need to decide if I’m a utilitarian (and if so, what kind of utilitarian!) or maybe some other kind of consequentialist or maybe I have a more Kantian view. So then depending on those answers, I can say “killing Greg Mankiw to steal the money in his pocket is wrong because…” and then lay the whole thing out.

I think what Mankiw is implying with the “smorgasboard” argument is that this is how people should actually engage in moral reasoning. So if I find myself uncertain about a broad question in ethical theory, this uncertainty must logically inflict my first-order moral judgments. Maybe killing Greg Mankiw really is okay? And if I’m not uncertain, if I say “the reason it’s wrong to kill Greg Mankiw and steal his money is that the murder would reduce net utility” then the murderer can counter with “well, if you believe in utilitarianism, you ought to believe in a height tax.” Then I say “well that sounds wrong!” And then, having debunked utilitarianism, Mankiw gets shot and everyone agrees that justice has been done.

Something’s gone wrong there. We don’t abandon considered convictions about normative issues that quickly. Murder is wrong. If forced to contemplate the alleged contradiction, there are a bunch of things we might want to consider. Maybe the analysis of the height issue has gotten something wrong, utility-wise. After all, though the paper is clever, it’s hardly a comprehensive review of all of the hedonic issues in play. Or maybe utilitarianism isn’t the best theoretical grounding for the conviction that murder is wrong. Or, maybe the height tax thing actually is a good idea, albeit an unrealistic one. But since this isn’t a “live” subject of political controversy, and since there seem to be a lot of other more clear-cut policy issues, we decide to spend our time and energy thinking about less outlandish policy suggestions.